New view of a stellar nurseryEUROPEAN SOUTHERN OBSERVATORY NEWS RELEASE zEsQcH.jpg (70.66 kB . 1440x900 - viewed 9386 times)Credit: European Southern ObservatoryOrion the Hunter is perhaps the best-known constellation in the sky, well placed in the winter for observers in both the northern and southern hemispheres, and instantly recognisable. Just below Orion's belt (three distinctive stars in a row), the hilt of his sword holds a great jewel in the sky, the beautiful Orion Nebula. Bright enough to be seen with the naked eye, the nebula, also known as Messier 42, is a wide complex of gas and dust, illuminated by several massive and hot stars at its core, the famous Trapezium stars. For astronomers, Orion is surely one of the most important constellations, as it contains one of the nearest and most active stellar nurseries in the Milky Way, the galaxy in which we live. Here tens of thousands of new stars have formed within the past ten million years or so - a very short span of time in astronomical terms. For comparison: our own Sun is now 4,600 million years old and has not yet reached half-age. Reduced to a human time-scale, star formation in Orion would have been going on for just one month as compared to the Sun's 40 years.

In fact, located at a distance of 1500 light years, the Orion Nebula plays such an important role in astrophysics that it can be argued that our understanding of star formation is for a large part based on the Orion Nebula.

It is thus no surprise that the Orion Nebula is one of the most studied objects in the night sky.

Cassini photos thrill, mystify scientistsNew pictures of Saturn's enigmatic moon Titan, taken by cameras aboard the Cassini probe that are capable of penetrating the thick smog-like haze that blankets the frigid world, show strange looking surface features and a deck of methane clouds the size of Arizona. But so far, the instruments have not detected reflections from the surfaces of lakes or small seas of liquid hydrocarbons many scientists believe must form in the ultra-cold environmentBut like the sun glint off rivers and lakes visible from airplanes on Earth, the reflections in question can only be seen in a small region of Titan, about 1 percent of the visible surface, based on the relative positions of the sun and Cassini.

"If we go by 30 times and we haven't seen it, we're going to start getting worried," said Kevin Baines, a member of Cassini's Visual Infrared Mapping Spectrometer team. "But I'd say so far, just going by once, it may have been that the specular reflection point was a continent, a dry area. So the planet could have plenty of liquids and we just got faked out. We don't know," he said in a telephone interview. "It's just 1 percent of the planet, we shouldn't reach any conclusions from that."

Cassini's first flyby of Titan, the day after the craft braked into orbit around the ringed planet, was at a distance of more than 200,000 miles. In October, the nuclear-powered probe will pass within just 745 miles of Titan and "we really expect to get a great view then," said Elizabeth Turtle, a member of the Cassini imaging team.

Piercing the ubiquitous layer of smog enshrouding Titan, this combination of images from the Cassini visual and infrared mapping spectrometer reveals an exotic surface covered with a variety of materials in the southern hemisphere. Image: NASA/JPL/University of Arizona.A mosaic of Titan's south polar region acquired as Cassini passed by at a range of 339,000 kilometers (210,600 miles) on July 2. These images were acquired through special filters designed to see through the thick haze and atmosphere. The surface features become more blurry toward the limb, where the light reflected off the surface must pass through more atmosphere before reaching the camera. The bright spots near the bottom represent a field of clouds near the south pole. Image: NASA/JPL/Space Science Institute.

The best view ever of Saturn's rings in the ultraviolet indicates there is more ice toward the outer part of the rings, hinting at ring origin and evolution, say two University of Colorado at Boulder researchers involved in the Cassini mission.From the inside out, the "Cassini division" in faint red at left is followed by the A ring in its entirety. The A ring begins with a "dirty" interior of red followed by a general pattern of more turquoise as it spreads away from the planet, which indicates denser material made up of ice. The red band roughly three-fourths of the way outward in the A ring is known as the Encke gap.This image shows the outer C and inner B rings respectively from left to right, with the inner B ring beginning a little more than halfway across the image. The general pattern is from "dirty" red particles to the denser ice shown in turquoise as the ringlets spread outward.The ring system begins from the inside out with the D, C, B and A rings followed by the F, G and E rings. The red in both images indicates sparser ringlets likely made of "dirty," and possibly smaller, particles than in the denser, icier turquoise ringlets.

<font size="4">How to fail at being a star</font id="size4"><font size="1">HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS NEWS RELEASE</font id="size1">

At the 13th Cambridge Workshop on "Cool Stars, Stellar Systems, and the Sun," Dr. Kevin L. Luhman (Harvard-Smithsonian Center for Astrophysics) announced the discovery of a unique pair of newborn brown dwarfs in orbit around each other. Brown dwarfs are a relatively new class of objects discovered in the mid-1990s that are too small to ignite hydrogen fusion and shine as stars, yet too big to be considered planets. "Are brown dwarfs miniature failed stars, or super-sized planets, or are they altogether different from either stars or planets?" asks Luhman. The unique nature of this new brown dwarf pair has brought astronomers a step closer to the answer press1_sm.jpg (11.67 kB . 175x137 - viewed 9143 times)Newly discovered young brown dwarfs with masses of 50 and 25 times the mass of Jupiter orbit each other at a distance of about 20 billion miles (six times the distance of Pluto from the Sun). Credit: K. Luhman (Harvard-Smithsonian Center for Astrophysics

One possible explanation for the origin of brown dwarfs is that they are born in the same way as stars. Stars form in huge interstellar clouds in which gravity causes clumps of gas and dust to collapse into "seeds," which then steadily pull in more and more material until they grow to become stars. However, when this process is studied in detail by computer, many simulations fail to produce brown dwarfs. Instead, all the seeds grow into full-fledged stars. This result led some astronomers to wonder if brown dwarfs and stars are created in different ways.

"In one alternative that has been proposed recently," explains Luhman, "the seeds in an interstellar cloud pull on each other through their gravity, causing a slingshot effect and ejecting some of the seeds from the cloud before they have a chance to grow into stars. These small bodies are what we see as brown dwarfs, according to that hypothesis." Testing these ideas for the birth of brown dwarfs is hampered by the fact that brown dwarfs are normally extremely faint and hard to detect in the sky. For most of their lives, they are not hot enough to ignite hydrogen fusion, so they do not shine brightly like stars, and instead are relatively dim like planets. However, for a short time immediately following their birth, brown dwarfs are relatively bright due to the leftover heat from their formation. As a result, brown dwarfs are easiest to find and study at an age of around 1 million years, which is newborn compared to the 4.5 billion year age of our Sun.

<font size="4">Clearing Up Blurry Vision: Scientists gaze toward causes of myopia</font id="size4">Next time you can't make out a distant highway sign, blame your parents. Scientists in the United Kingdom have found that myopia, or nearsightedness, is predominantly hereditary, and they're beginning to unravel the genetic mechanism that causes the vision problem.

Roughly a third of people in the United States suffer from myopia—they clearly see close objects, such as words in a book, but things in the distance appear blurry. The anatomic root of the problem is an elongation of the eye as it grows, causing incoming light to focus in front of the retina, instead of squarely on it, explains Christopher J. Hammond of St. Thomas' Hospital in London.

Using a noninvasive technique, Hammond measured the sizes of the eyeballs of 280 sets of fraternal adult twins and 226 sets of identical twins. By mathematically modeling the differences in the eye sizes, Hammond found that genes accounted for 89 percent of nearsightedness, farsightedness, and other refractive vision problems, he reports in the August American Journal of Human Genetics.

To investigate what regions of DNA in the general population might have a connection to myopia, Hammond scanned the entire genome of the fraternal twins and found four sections linked to the eye problem. The most strongly linked segment contains 44 genes, including one specified as PAX6, which is already well-known to vision researchers. From fruit flies to humans, this gene is fundamental to eye growth in nearly all species that scientists have examined. To investigate what regions of DNA in the general population might have a connection to myopia, Hammond scanned the entire genome of the fraternal twins and found four sections linked to the eye problem. The most strongly linked segment contains 44 genes, including one specified as PAX6, which is already well-known to vision researchers. From fruit flies to humans, this gene is fundamental to eye growth in nearly all species that scientists have examined.

If scientists can determine the genetic mechanisms for myopia, they might develop targeted pharmaceutical agents that can halt or slow the excessive eye growth that causes it.

Many claim there is not one kind of intelligence, but at least eight different types, including verbal, spatial and emotional intelligence

Argument rages as to whether intelligence is biologically or socially determined

The brain weighs less than 2.5% of our total bodyweight, but accounts 20% of our energy consumption when we're at rest. It burns oxygen and glucose at ten times the rate of other body organs

Each year 10,000 people take the MENSA IQ test - 2,500 pass to become members. Over the last century, the UK's average IQ has risen about 3 points every decade

IQ depends on your culture, class and gender because of the way tests are written. Controversially, in the 1920s IQ tests were used to assess the suitability of immigrants for US citizenship

What is intelligence?

Defining intelligence is highly problematic. Is there an 'intelligence' that equips us to solve all kinds of problems and answer all questions, regardless of their nature? Or are there different intelligences that help us deal with particular problems and solutions? The scientific community is divided on the issue.One of the main tenet's underpinning the idea of a single entity 'intelligence' is the concept of 'General Intelligence', or 'g'. Devised by English Psychologist, Charles Spearman, in the early 20th Century 'g' was a statistical measure of performance across a variety of tests.

Spearman found that the same people who did well in a variety of mental tests tended to use a part in their brains that he termed 'g'. This 'g' laid the foundation for the notion of a single intelligence, which enables us to undertake everyday mental tasks.

A recent study seems to endorse Spearman's theory. Research has found that a part of the brain called the 'lateral prefrontal cortex' is the only area of the brain to increase in blood flow when volunteers tackle complicated puzzles.

Spearman's concept, however, is still highly controversial with many people questioning both the statistical process and the simplistic nature of 'g'. There is also a body of research that states that our mental ability is a function of social factors such as education and not one's inherent biological make-up.Intelligence and the brainThe early Greeks thought the brain was the home of your soul, rather than your intellect. They believed that thinking happened somewhere around the lungs! Not until the seventeenth and eighteenth centuries was the brain seen as an organ of intelligence and thought, when the concept of the mind emerged.

Using new forms of technology, scientists have been able to look at how the brain performs when we undertake different tasks. Roll the pointer over the brain below to find out how our brain processes language.

The moon with the split personality, Iapetus, presents a perplexing appearance in the latest images snapped by the Cassini spacecraft.One hemisphere of the moon is very dark, while the other is very bright. Scientists do not yet know the origin of the dark material or whether or not it is representative of the interior of Iapetus.

Iapetus (pronounced eye-APP-eh-tuss) is one of Saturn's 31 known moons. Its diameter is about one third that of our own moon at 1,436 kilometers (892 miles). This image was taken in visible light with the Cassini spacecraft narrow angle camera on July 3, 2004, from a distance of 3 million kilometers (1.8 million miles) from Iapetus. The brightness variations in this image are not due to shadowing, they are real.

During Cassini's four-year tour, the spacecraft will continue to image Iapetus and conduct two close encounters. One of those encounters, several years from now, will be at a mere 1,000 kilometers (622 miles).

Iapetus was discovered by the Italian-French astronomer Jean Dominique Cassini in 1672. He correctly deduced that the trailing hemisphere is composed of highly reflective material, while the leading hemisphere is strikingly darker.

This sets Iapetus apart from Saturn's other moons and Jupiter's moons, which tend to be brighter on their leading hemispheres. Voyager images show that the bright side of Iapetus, which reflects nearly 50 percent of the light it receives, is fairly typical of a heavily cratered icy satellite. The leading side consists of much darker, redder material that has a reflectivity of only about 3 to 4 percent.Iapetus is odd in other respects. It is in a moderately inclined orbit, one that takes it far above and below the plane in which the rings and most of the moons orbit. It is less dense than many of the other satellites, which suggests a higher fraction of ice or possibly methane or ammonia in its interior.

The first chocolate barsIn the 1800s, solid chocolate became popular, with the invention of moulding processes. Mechanical grinders crushed cocoa beans to a fine powder that could be heated and poured into moulds, forming shapes as it cooled.

Dutchman Coenrad Van Houten perfected the extraction of cocoa butter from cocoa beans in 1825. The beans are crushed to a paste, which is subjected to very high pressure, forming chocolate liquor and cocoa butter. The extracted butter is smoothed and treated to remove any odours.

In the 1880s, Rudolphe Lindt of Switzerland started adding extra cocoa butter during chocolate manufacture, to make it smoother and glossier. Cocoa butter melts at around 97°F, which is human body temperature. That's why chocolate melts in the mouth. cocoapods-trunk-image.jpg (135.89 kB . 1024x600 - viewed 9201 times)Some Cocoa Pods hanging around yesterday

Chocolate craving

The love of chocolate goes beyond the call of sweetness. Chocolate can induce craving in a way that other sugary products like toffee or marshmallow don't. Chocolate makes us feel good, but can it really be addictive?General sweetness aside, there are various chemical elements specific to chocolate that may help to stimulate cravings. In fact, chocolate contains over 300 chemicals and it is not known how all of these affect humans. best-hot-chocolate-recipe-coconut-milk.jpg (74.02 kB . 575x384 - viewed 9227 times)A Cup of chocolate...err..yesterday !

Many women report particular chocolate cravings when pre-menstrual. This is possibly because chocolate contains magnesium, a shortage of which can exacerbate pre-menstrual tension. Similar cravings during pregnancy could indicate mild anaemia, which chocolate's iron content may help to cure.

Love drug?

Chocolate contains a natural 'love drug'. Tryptophan is a chemical that the brain uses to make a neurotransmitter called serotonin. High levels of serotonin can produce feelings of elation, even ecstasy - hence the name of the designer drug that also works by increasing serotonin levels. ggggg.png (168.89 kB . 293x252 - viewed 9197 times)A chocolate orgy earlier today !

Lust drug?While tryptophan could be considered 'chocolate's ecstasy', another chemical called phenylethylamine has earned the nickname 'chocolate amphetamine.' High levels of this neurotransmitter help promote feelings of attraction, excitement, giddiness and apprehension. Phenylethylamine works by stimulating the brain's pleasure centres and reaches peak levels during orgasm.

Chocolate chemistryLike other sweet food, chocolate stimulates the release of endorphins, natural body hormones that generate feelings of pleasure and well-being.General sweetness aside, there are various chemical elements specific to chocolate that may help to stimulate cravings. In fact, chocolate contains over 300 chemicals and it is not known how all of these affect humans.

Many women report particular chocolate cravings when pre-menstrual. This is possibly because chocolate contains magnesium, a shortage of which can exacerbate pre-menstrual tension. Similar cravings during pregnancy could indicate mild anaemia, which chocolate's iron content may help to cure.

NASA's Mars rovers roll into martian winterAs winter approaches on Mars, NASA's Opportunity rover continues to inch deeper into the stadium-sized crater dubbed "Endurance." On the other side of the planet, the Spirit rover found an intriguing patch of rock outcrop while preparing to climb up the "Columbia Hills" backward. This unusual approach to driving is part of a creative plan to accommodate Spirit's aging front wheel.

A picture from Spirit. Credit: NASA/JPL

Spirit, with an odometer reading of over 3.5 kilometers (2.2 miles), has already traveled six times its designed capacity. Its right front wheel has been experiencing increased internal resistance, and recent efforts to mitigate the problem by redistributing the wheel's lubricant through rest and heating have been only partially successful.

A new picture from Opportunity showing the floor of Endurance Crater. Credit: NASA/JPLOpportunity will roll down even farther into the crater in the next few days to see if this trend continues. It also will investigate a row of sharp, teeth-like features dubbed "Razorback," which may have formed when fluid flowed through cracks, depositing hard minerals. Scientists hope the new data will help put together the pieces of Meridiani's mysterious and watery past. "Razorback may tell us more about the history of water at Endurance Crater," said Dr. Jack Farmer, a rover science-team member from Arizona State University, Tempe. SOURCE: SPACEFLIGHTNOW

meteorite.jpg (12.84 kB . 398x263 - viewed 9093 times)While rovers and orbiting spacecraft scour Mars searching for clues to its past, researchers have uncovered another piece of the red planet in the most inhospitable place on Earth -- Antarctica.

CREDIT: NASA

The new specimen was found by a field party from the U.S. Antarctic Search for Meteorites program (ANSMET) on Dec. 15, 2003, on an ice field in the Miller Range of the Transantarctic Mountains, roughly 750 km (466 miles) from the South Pole. This 715.2-gram (1.6-pound) black rock, officially designated MIL 03346, was one of 1358 meteorites collected by ANSMET during the 2003-2004 austral summer.

Doughnut-shaped cloud has 'black hole' fillingNASA NEWS RELEASEAn international team of scientists has found more evidence that massive black holes are surrounded by a doughnut-shaped gas cloud which, depending on our line of sight, blocks the view of the black hole in the center.

Using two European Space Agency orbiting observatories, INTEGRAL and XMM-Newton, scientists looked "edge on" into this doughnut, called a torus, to see features never before revealed in such clarity. They could infer the doughnut structure and distance from the black hole by virtue of light that was either reflected or completely absorbed. How the doughnut forms, however, remains a mystery. Black holes are objects so dense and with gravity so strong that not even light can escape from them. Scientists say that "supermassive" black holes are located in the cores of most galaxies, including our Milky Way galaxy, and contain the mass of millions to billions of suns confined within a region no larger than our Solar System.

Supermassive black holes appear to be surrounded by a hot, thin disk of accreting gas and, farther out, the thick doughnut-shaped torus. Astronomers often view black holes that are aligned face-on or at a slight angle in relation to Earth, thus avoiding the dark, enshrouding torus to study the hot accretion disk.

This link downloads a larger version of the above piccy but be warned, if you have a slow connection (I don't..so there nyahh nyahh nyahh !!) it might take a while (700k)http://imgsrc.hubblesite.org/hu/db/2004/21/images/a/formats/print.jpg

Like a photographer clicking random snapshots of a crowd of people, NASA's Hubble Space Telescope has taken a view of an eclectic mix of galaxies. In taking this picture, Hubble's Advanced Camera for Surveys was not looking at any particular target. The camera was taking a picture of a typical patch of sky, while Hubble's infrared camera was viewing a target in an adjacent galaxy-rich region.

The jumble of galaxies in this image, taken in September 2003, includes a yellow spiral whose arms have been stretched by a possible collision [lower right]; a young, blue galaxy [top] bursting with star birth; and several smaller, red galaxies.

But the most peculiar-looking galaxy of the bunch -- the dramatic blue arc in the center of the photo -- is actually an optical illusion. The blue arc is an image of a distant galaxy that has been smeared into the odd shape by a phenomenon called gravitational lensing. This "funhouse- mirror effect" occurs when light from a distant object is bent and stretched by the mass of an intervening object.

In this case the gravitational lens, or intervening object, is a red elliptical galaxy nearly 6 billion light-years from Earth. The red color suggests that the galaxy contains older, cooler stars.

The distant object whose image is smeared into the long blue arc is about 10 billion light-years away. This ancient galaxy existed just a few billion years after the Big Bang, when the universe was about a quarter of its present age. The blue color indicates that the galaxy contains hot, young stars.

Deep-Sea Cukes Can't Avoid the Weather: El Niño changes life 2.5 miles downLOW LIFE. The sea cucumber Scotoplanes globosa, a species with appendages, lives miles below the ocean surface but grew more abundant after an El Niño and a La Niña.

That's the conclusion of a 14-year study of sea cucumbers, brittle stars, and other mobile bottom dwellers off the California coast, says Henry A. Ruhl of Scripps Institution of Oceanography in La Jolla, Calif. What links the top to the bottom is the fall of dead plankton and other debris that provides food in the depths, he and Kenneth L. Smith Jr., also of Scripps, say in the July 23 Science. They link changes in the abundance of certain species some 2.5 miles underwater to the El Niño and La Niña weather shifts between 1997 and 1999.

Marine scientists have discussed possible associations between year-by-year surface weather and deep-sea life. But "there are few actual examples in the modern ocean," comments Andrew Gooday of the Southampton Oceanography Center in England.

"There has been a paradigm shift," Gooday says. "If you go back 30 years, the idea was that the deep-ocean floor was very stable." In the 1970s, though, biologists found evidence that even creatures living at great depths reproduce in accord with the surface seasons. As evidence has appeared for longer-term changes in deep-sea communities, marine scientists have come to see the ocean floor "as a more dynamic environment," says Gooday.

A day after entering orbit around Saturn, Cassini sped silently past Titan, imaging the moon's south polar region. This natural color image represents Cassini's view only about two hours after closest approach to the moon.

Credit: NASA/JPL/Space Science InstituteThe superimposed coordinate system grid in the accompanying image at right illustrates the geographical regions of the moon that are illuminated and visible, as well as the orientation of Titan -- lines of longitude converge on the South Pole above the center of the image. The yellow curve marks the position of the boundary between day and night on Titan.

Images taken through blue, green and red filters were combined to create this natural color view. The images were obtained using the Cassini spacecraft wide angle camera on July 2, 2004, from a distance of about 347,000 kilometers (216,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase angle of 62 degrees. This view is an improvement in resolution of nearly a factor of four over the previously released natural color view of Titan (see PIA06081). The image scale is 21 kilometers (13 miles) per pixel.

Astronomers studying data from the National Science Foundation's Very Long Baseline Array (VLBA) and other telescopes have concluded that a binary pair of stars forming an energetic microquasar was blasted out of the cluster in which it was born by a supernova explosion some 1.7 million years ago. This is the first time that a fast-moving stellar pair has been tracked back to a specific star cluster.

The scientists analyzed numerous observations of a microquasar called LSI +61 303, and concluded that it is moving away from a star cluster named IC 1805 at nearly 17 miles per second.

A microquasar is a pair of stars, one of which is either a dense neutron star or a black hole, in which material sucked from a "normal" star forms a rapidly-rotating disk around the denser object. The disk becomes so hot it emits X-rays, and also spits out "jets" of subatomic particles at nearly the speed of light.

Encircled in purple stratospheric haze, Saturn's largest moon, Titan, appears as a softly glowing sphere in this colorized image taken on July 3, 2004, one day after Cassini's first flyby of that moon. Titan has a dense atmosphere composed primarily of nitrogen with a few percent methane. The atmosphere can undergo photochemical processes to form hazes.

Credit: NASA/JPL/Space Science Institute

Images like this one reveal some of the key steps in the formation and evolution of Titan's haze. The process is thought to begin in the high atmosphere, at altitudes above 400 kilometers (250 miles), where ultraviolet light breaks down methane and nitrogen molecules. The products are believed to react to form more complex organic molecules containing carbon, hydrogen and nitrogen that can combine to form the very small particles seen as haze.

This ultraviolet view of Titan has been falsely colored. The main body is colored pale orange as seen in true color images. Above the orange disc are two distinct layers of atmospheric haze that have been brightened and falsely colored violet to enhance their visibility. It is not currently understood why there are two separate haze layers. This and other questions await answers as the four-year Cassini tour continues, with many more planned flybys of Titan. The upcoming October 2004 flyby of Titan will be 30 times closer than that of July 2.

NASA's Terra satellite captured this true-color image of Hurricane Alex, the first Atlantic hurricane of the season, at noon EDT on Tuesday, August 3. Around that time, the Category 2 storm was pounding North Carolina's Outer Banks with winds of up to 100 miles an hour. It's expected to eventually turn east and head out to sea.

The resolution on this photo, from Terra's Moderate Resolution Imaging Spectroradiometer (MODIS), is 2 kilometers per pixel

A new image from NASA's Spitzer Space Telescope shows the shimmering embers of a dying star, and in their midst a mysterious doughnut-shaped ring.

"Spitzer's infrared vision has revealed what could not be seen before - a massive ring of material that was expelled from the dying star," said Dr. Joseph Hora, a Spitzer scientist at the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. "The composition of the ring and how it formed are mysteries we hope to address with further Spitzer studies."

Credit: National Astronomical Observatory of JapanThese cosmic beauties last a relatively brief time, about a few thousand years, in the approximately 10-billion-year lifetime of a star. The name "planetary nebula" came from early astronomers who thought the rounded clouds looked like planets.:

Lighting the Way for Water: New strategy for steering drops with finesse

Alexandra Goho

Several years ago, a team of researchers in Japan used a beam of light to move drops of oil around on a surface. They could not do the same thing with water drops, however. Now, with inspiration from lotus leaves, a second team has succeeded in manipulating water with a beam of ultraviolet light. That could open new routes for controlling biochemical reactions, the scientists say.

PHOTO SWITCH. Ultraviolet light can move a water drop along a rough photosensitive surface (left), whereas a drop on a smooth photosensitive surface (right) stays put and spreads out.R. Rosario

The difficulty of moving drops of water with light stems from the way water molecules interact with surfaces. In previous experiments, Antonio Garcia and his colleagues at Arizona State University in Tempe tried to sidestep that challenge by manipulating the drops on very smooth surfaces. Yet, while the front end of the drop would move toward the light, the back end would stick to the surface. The new water-controlling tactic could improve microfluidic chips that many researchers are designing for applications ranging from medical diagnostics to environmental monitoring. In such devices, microscopic valves and pumps direct tiny amounts of fluid through specified channels and into specific microchambers

Bridging the gap between the nanoworld and the macroworld, researchers have created a membrane out of carbon nanotubes and demonstrated its potential for filtering petroleum and treating contaminated drinking water.

Scientists have long valued carbon nanotubes for their high strength and thermal properties yet it's been a challenge to assemble nanotubes into useful materials large enough for people to hold in their hands.

CLEAR PASSAGE. The wall of this tube-shaped filter is made of a single layer of densely packed carbon nanotubes.

Researchers at Rensselaer Polytechnic Institute in Troy, N.Y., and Banaras Hindu University in Varanasi, India, have now devised a method for making such large-scale structures and found an application for them.

The researchers injected a solution of benzene and ferrocene—the materials needed to assemble the carbon nanotubes—into a stream of argon gas and then sprayed the mixture into a quartz tube. The tube was located inside a furnace heated to 900°C.

A dense forest of carbon nanotubes formed on the inner walls of the quartz tube, yielding a hollow black cylinder. The researchers carefully removed the cylinder, which measured several centimeters long and up to a centimeter in diameter. It was composed of trillions of nanotubes. Each nanotube was only a few hundred microns long, essentially the thickness of the carbon cylinder's wall.